Igor functions as Milk's dedicated interface robot and personal butler. His strong work ethic stems from constantly navigating Milk's unpredictable and demanding nature. When Milk acquires her inventor's license, Igor becomes her designated interface robot, temporarily adopting the name "Sebastian," though this change is not lasting.

Five years later, during Milk's rise as a famous superstar idol on Planet Sharaku, Igor evolves into her manager. His physical design updates include longer legs. Despite Milk's persistent selfish tendencies and underdeveloped inventor skills, Igor remains steadfast, balancing managerial duties with his core butler responsibilities. His consistent commitment supports Milk through her various life phases, maintaining his role as her primary assistant across both seasons.